Analog Front-End Circuit Design Of Multifunctional Instrument

Nowadays, electronic equipment in the direction of diversification and intelligentization constantly open up, along with electronic equipment to achieve the function also change rapidly. Accordingly this will lead to electronic equipment system is more complicated. In order to make the detection performance of a test system cope with the current pace of development in electronics industry, developed a new concept of automatic test system is more urgent. For this purpose, the concept of multi-functional synthetic instrument came into being.Multi-functional synthetic instrument is a modular hardware and software testing solutions. The core idea is that through a universal hardware module structure and reconfigurable of software to accomplish the diverse goals of test function. Therefore, it will be more flexible than the traditional single-function instruments. This paper research the synthesis instrument of multi-functional currently composed by three parts. The Multi-functional synthetic instrument is a automatic test system that use PowerPC architecture as embedded system platform’s CPU and based on the PCIE bus system for the transmission protocol.In this paper, the research missions is to design a specific process of Multi-functional synthetic instrument’s analog channel, which includes conditioning process of three kinds of instrument, the first is conditioning process of digital oscilloscope for input signal; the second is conditioning process of arbitrary waveform generator for excitation signal; the last is conditioning process of data acquisition card for AC signal. It can made the output signal satisfied the requirements of digital circuit after through the analog channel of digital oscilloscope and data acquisition card, while the signal generator output closer to the needs of users. The research contents consist of following:1) Signal conditioning process is mainly realized the signal attenuation, amplification, impedance conversion, and filtering process for different frequencies signal.2) The trigger circuit includes the conditioning process of trigger signal、the choice of trigger source signal.3) The control signal circuit refers to the system’s control of logic state and the adjustment of bias level. And it can ensure the working sequence of system.4) The part of power supply completes different voltage supplies and provides the ultra-low noise power supply for system.5) Signal integrity analysis. It lists the impact on signal integrity in this system, while elaborates layout planning form some important chips and circuit board.